Miniature nuclear power stations available within decade

In less than a decade remote villages may be able to purchase their own miniature nuclear power plants to secure reliable carbon-free electricity or complement renewable installations.

There has been a lot of talk lately about small modular reactors (SMR’s), small-scale versions of pressurised water reactors, the most common technology to be found inside nuclear power plants. These modular units, completely manufactured in factories and easily assembled on site, could deliver up to 300MW of power each and could present a viable alternative to building massive plants such as Hinkley Point.

However, uranium enrichment firm URENCO has decided to go even further and develop a miniature nuclear power plant so small and cheap that it could power a single town or a factory, essentially empowering users to have their own nuclear power plant in their own back yard.

“A single unit would occupy an area the size of two squash courts,” explained Paul Harding of URENCO, overseeing the project called U-Battery, which is a partnership with UK companies including Amec Foster Wheeler, Atkins, Cammell Laird and Laing O’Rourke.

“The footprint of each unit is about the penalty area of a football pitch. Each unit is designed to give 10 megawatts of thermal output of which around 40 per cent can be converted into electricity, so you can get four megawatts of electricity from a single installation.”

Unlike the larger SMRs, U-Battery is a high temperature gas cooled reactor akin to currently developed generation IV nuclear reactors. It uses grain-like TRISO fuel that is not designed for reprocessing but spent after one use.

According to Harding, the technology is perfectly safe by design and doesn’t pose any risk to its users or the environment.

“The U-Battery is designed to operate at about 700℃ and you do not challenge integrity of the fuel to at least 1600℃ so there is a great margin,” Harding said.

“TRISO fuel is inherently safe. It consists of grains of uranium oxide that are coated in three layers of ceramic material, which ensures that fission products do not escape from the inner kernel.”

The remotely controlled U-Battery was designed with renewable energy generation in mind and the team envisions it could serve as a back-up power generator for solar and wind power plants.

“It can be turned on within seconds so if the wind stops blowing, you can turn a U-Battery on and make up for the renewable intermittency,” explained Harding.

It could also offer a carbon-free alternative to polluting diesel power generators and the somewhat cleaner gas cogeneration plants.

The team is already negotiating with authorities of the Canadian province of Ontario to have U-Batteries tested in some of the remote northern communities that are not connected to the utility grid.

“In Canada there is quite a lot of demand to find an alternative to diesel-powered cogeneration plants because the cost of electricity produced using diesel is large compared to, for example, what we are used to in the UK for domestic energy charges,” explained Harding.

“In the UK, the most likely deployment is at heavy industry sites – in cement making, brick making or steel – as an alternative to current gas and diesel embedded power plants. It would help them not only to reduce emissions but also provide a source of energy, where they would know what the price would be for the next 20 or 30 years.”

The U-Battery was developed by a joint team from the UK University of Manchester and the Dutch University of Delft as part of a competition sponsored by URENCO in 2008.

URENCO expects to have the first U-Batteries up and running as early as 2024, six years earlier than what is expected for the larger SMRs.

In a report published in late September the UK’s Energy Technologies Institute predicted that if proper government support is in place, the SMR technology could be market ready in 2030, generating carbon-free power but also providing heat for local communities.